Hello. Here is a short guide on factorials.

**The Factorial**

Before going into the definition of factorials. Here are some examples of factorials.

As you can see, a factorial is a compact way of expressing the multiplication of descending (or ascending) positive whole numbers.

With factorials, the general case is:

or

for

There are also some special cases with and .

**Division With Factorials**

You may encounter fractions with factorials in the numerator and in the denominator. Here are some examples.

__Example One__

__Example Two__

__Example Three__

__Example Four__